"Yeah!" responded more than 200 voices, several people springing up to form a slow-moving hora conga line through the crowded WHYY studio, where they'd just spent nearly three hours watching a line-up of about a dozen performers and dignitaries.

"I wish all seders were like this," said Gershon Cattan, 35, of South Philadelphia.

Music, poetry and dance were the mediums; uniting community was the theme at the Gershman Y's "Philadelphia Seder." Attendees paid $75 apiece for the Sunday night program, which included a three-course catered meal.

As for the matter of tradition, well, the plan was to create new ones, organizers said. There were no Haggadahs or seder plates, no ritual consumption of a matzah sandwich or search for the hidden afikomen. Instead, guest presenters had the liberty of translating or expounding on their assigned portion of the seder however they saw fit.

"Just like the rabbis of old, we're using things from our own surroundings of Philadelphia and reimagining all the steps of the seder," explained emcee Eli Freedman, an assistant rabbi at Reform Congregation Rodeph Shalom.

Following the first cup of wine, a dancer from Brian Sanders' JUNK hobbled onstage masked in a rubber caricature of an old man. Swaying to a klezmer melody, he splashed his hands in a bowl of water and poured a glass of red wine. A few gulps sent him onto the table in a joyous dance, followed by a duet with a young woman (presumably a drunken hallucination) and then an acrobatic display by another old man character.

In lieu of dipping greens, the audience heard from two high schoolers in the Philly Youth Poetry Movement. Then it was on to Matt Bar, a Jewish rapper and educator who recruited volunteers to help him "spit" the Ten Plagues.

Several presenters noted how far the Jewish people have come since their transition from slavery. Yet "the search for social justice goes on," Jane Golden said, referencing the troubled neighborhoods she frequents during her work as the executive director of the city's Mural Arts Program.

"In this season of rebirth, I ask all of you to join together to change despair into hope," Golden continued during a toast. "We have the responsibility, but more importantly, we have the capacity to respond."

Echoing Golden, folk singer Chana Rothman urged the crowd not to shy away from uncomfortable conversations that need to happen when injustice emerges. She dedicated a song called "Gates of Justice," to Trayvon Martin, the unarmed Florida high school student who was shot and killed in late February by a neighborhood-watch volunteer.

"In this time when people really think they can solve problems by using a gun, what is strength? What is love?" Rothman asked. "Truly the gates of justice are not supposed to open for certain people but for all of us."

The program drew a fair number of non-Jewish participants, including volunteer organizers Maurice Baynard and Erica Atwood, both African-American.

Exposing people to new ideas was part of the point, said Baynard, 45, a biomedical researcher and lecturer at Drexel University. He grew up with many Jewish friends, so taking part in a Passover seder was nothing new.

But it was a first for Atwood, 37, a community engagement specialist for the city. Despite coming from a very different background, Atwood said the event felt like a family reunion.

Just as dessert was served, Nelson strode into the room in a long embroidered robe and launched into a gospel variation of "Adon Olam."

"I know you know that I'm Jewish, but did you know that I was black as well?" Nelson asked rhetorically, grinning at his audience.

And then he was off singing again, punctuating "Hinei Ma Tov" with a Louis Armstrong-inspired scat.

"I've been to a lot of weird seders, but not like this," said Lizzie Burrows, 24, a program coordinator for the Chevra, a Jewish young professionals group, who just moved to town in December. Burrows said she was moved by the diversity of the audience and several of the performers. One of the young poets even brought her to tears, she said.

It "made me think about the seder in a new way." As Nelson put it, she said, sometimes you have to sing to God in new ways so the same songs don't get boring.